Internal combustion engines may be boosted by turbochargers or superchargers to increase engine performance, such as engine power output. Additionally, some internal combustion engines may include deactivatable cylinders to enable a portion of the engine cylinders to be deactivated when the power provided by the cylinders is not needed such as during low load operation. It will be appreciated that deactivation may include inhibiting intake air flow to the cylinder, fuel injection into the cylinders, and/or spark delivered to the cylinders in the case of a spark ignition engine.
Attempts have been made to incorporate both turbochargers and cylinder deactivation into internal combustion engines. However, the Inventors have recognized several drawbacks with engines utilizing both cylinder deactivation and boosting devices. For example, during cylinder deactivation the turbocharger may not be configured to efficiently deliver boost to the cylinders due to the decreased airflow. As a result, engine efficiency is decreased.
As such in one approach, an internal combustion engine system is provided. The internal combustion engine includes an active cylinder, a selectively deactivatable cylinder, the active cylinder and selectively deactivatable cylinder each coupled to an intake system and exhaust-gas discharge system, an exhaust-gas turbocharger having a turbine positioned in the exhaust-gas discharge system and a compressor positioned in the intake system, a blower positioned in the intake system downstream of the compressor, and a bypass line bypassing the blower and including a shut-off valve. Providing the blower in the intake system enables increased boost to be supplied to the cylinders during partial cylinder deactivation when the boost provided by the turbocharger decreases due to decreased exhaust gas flow through the turbine. In this way, combustion efficiency in the active cylinders can be increased during partial deactivation of the selectively deactivatable cylinder. As a result, engine efficiency and operation is improved during cylinder deactivation.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. Additionally, the above issues have been recognized by the inventors herein, and are not admitted to be known.